Theoretical studies of structures and stabilities of a new odd-numbered fullerene dimer: C₁₄₁

The possible isomers of a newly synthesized C₁₄₁ molecule are calculated using MNDO, AM1, PM3, B3LYP/3-21G, and B3LYP/6-31G(d) methods. The geometry optimizations showed that the isomer 8-8 has the lowest total energy in all 64 possible structures of C₁₄₁. Unlike those of C₁₃₀, C₁₄₀, etc., the C₁₄₁ 8-8 shows a new structure: two C₇₀ side cages open [6.6] ring junctions located at the equator (instead of cap) area to create new chemical bonds for the bridge atom. Theoretical measurements of the average length of the long and short axes of C₇₀ side cages in the C₁₄₁ molecule reveal that when two C₇₀ cages are connected with each other at the equators, their geometric shapes become more spherical compared with the pristine C ₇₀; this leads to a reduction of the molecular polarizability. Analysis of the local and global strain indicates that the global strain of C₇₀ monomer in the C₁₄₁ 8-8 is greatly reduced compared to the pristine C₇₀. The stable C₇₀ derivatives that are formed with reacted C - C bonds in the equator area may put new insights into fullerene chemistry, in particular, for C₇₀ to react with a large molecule. The results are discussed together with the experimental data.